Pulverizing and separating machine



Original Filed June l5, 1952 G. H. FRASER' PULVERIZING AND SEPARATING MACHINE 2 Sheets-Sheet 1 Jan. 30, 1940. G. H. FRASER PULVERIZING AND SEPARATING MACHINE Original Filed June l5, 1332 2 Sheets-Sheet 2 INVENTOP.

Patented Jan. 30, 1940 UNITED STATES PATENT oFFicE Application June 1.5, 1932, Serial No. 617,395

Renewed April 15, 1939 16 Claims.

This invention relates to combined pulverizing mills and air separators, and aims to provide certain improvements therein.

One such device is shown in my Patent No.

1,499,516, dated July 1, 1924, and others are shown in my Patents Nos. 1,834,094` and 1,834,- 095, dated Dec. 1, 1,931. The devices disclosed in these patents were nishing mills in which all the material fed into the mill must be fully pulverized, as no provision was made in them for the discharge of uncr'ushed material.

This invention aims to improve combined pulverizing and air separating mills, and to this end makes provision therein for the discharge below the return current passage thereof of uncrushed materialtherefrom, and provides them with various other features of improvement, all of which in their preferred form and utilization will be more fully set forth with reference to the accompanying drawings, in which Fig. l is a side elevation, partly in vertical aX- ial section of one type of combined pulverizer and air separator provided with the preferred form of my present improvements; Y

g5 Fig. 2 is a fragmentary plan view thereof partly broken away to show fragments of the drive gears, valve, fan blades and crushing chamber, and

Fig. 3 is a fragmentary horizontal section 30 thereof, cut approximately on the planes of the A lines 3-3 in Fig. 1.

In the type, shown in Figs. 1, 2 and 3, of a combined mill and air separator with which the preferred form of my present improvements is 35 shown as availed of,

A is a die or crushing element having an inner annular crushing face disposed around a vertical axis; f

B are rotatable crushing rolls or elements 40 within and eccentric of and each having a peripheral crushing face reciprocal to said face, for crushing material between said faces;

C is a disc or distribution means, for distributing material to be crushed to said faces;

4;; D is a supply means or vertical conduit having an orice above said disc, for supplying said material thereto;

E is a crushing chamber encircled by said die;

F is a rotary means for rotating said parts;

im G is a bearing or support means or frame for .said parts;

l-l is an outer casing or housing spaced around said die and chamber;

I is a blower means or fan blades within said 55 casing;

(ci. zas-45) J is a settling chamber or current passage within said casing;

K is a fine material intercepting means or lter within said casing;

L is a dust chamber below said filter; 5

M is a dust outlet from said dust chamber;

P is an annular casing above the die A and around and enclosing the chamber E and spaced concentrically within the casing H;

Q is an upper current and fine material discharge outlet from the chamber E to and in communication with the chamber J;

R is an annular casing below the die A and around and enclosing the chamber E; a

S is a lower current inlet to the chamber E 10 and in communication with the chamber J;

T is a vertically adjustable annular valve above the outlet Q;

U is an adjusting screw for the valve T;

n2 is an open dropper outlet from the cham- 20 ber E, inwardly of and extended through the inlet S and in communication from below the crushing elements, through said inlet, to below and eX- ternally of said chamber, for dropping coarser material from the latter;

W is a sustainer wall below the dropper outlet n2 and spaced below the inlet S, for receiving and sustaining below the latter said dropped material; v

X is a return current passage below the inlet S and above the wall W, and in communication from the chamber J, through said inlet, with the chamber E, for returning current to the latter;

A is an uptosser means inwardly of the inlet S and in communication therethrough from. above the wall W to within the chamber E, for uptcssing through said inlet and returning to the crushing elements within said chamber uncrushed material sustained on said wall, and

S is a chamber for the valve T.

These parts may be any usual or suitable parts for crushing material within the crushing chamber E, affording an endless current passage up through and down around the latter, and for causing a separating current to upfloat fine material from. the crushing elements within the crushing chamber into the settling chamber, and to return through the return current passage to the .lower inlet, and for permitting coarser material to drop below the crushing elements and through the returning current from the crushing chamber E on to the bottom wall W of the return current passage X, and for uptossing uncrushed materialfrom said wall to said elements, according to the usual principle of operation e is a vertical tubular shaft for the spoke means c;

f is a rockable collar on the shaft e; gis a bearing for the shaft e; h is a bevel gear keyed to and carrying the shaft e from the bearing g;

i is a bevel pinion meshing with the gear h;

i is a tubular shaft for the pinion i; k is a pulley for the shaft 9';

l are outwardly swingable arms on the outer ends of which the rolls B are journaled respectively so as to bear against the inner face of the n die A;

m is a ring hub on which the inner ends of the arms l are pivotally mounted;

n is a vertical tubular shaft within the shaft e and around the pipe D and carrying the hub m;

o is a rockable collar on the shaft n; .p is a bevel gear keyed to and carrying the shaft n;

q is a bearing for the gear p; r is a beveled pinion rotating the gear 22; s is a horizontal shaft within the shaft 7' and carrying the pinion r; t is a pulley for the shaft S; f f

u are springs outpressing the arms l and rolls B toward the die A; l

'v are screws for adjusting the tension of the springs u; D w are spoke means for the fan blades I; a: is a fan hub carrying the fan spokes w; y is a vertical tubular shaft around the shaft e and carrying the hub x; y e is a bevel gear fastened to the shaft y; 4,5 a is a bearing for the gear 2;

b is a bevel pinion rotating the gear z; A C is a horizontal tubular shaft around the shaft j and carrying the pinion b;

d is a pulley on the shaft c'; e is a lower wall of the frame G, below and carrying the bearing a', which carries the gear 2,

which carries the bearing y, which carries the gear h, which carries the b-earing q, which carries the gear p` in such manner that each of these gears and its vertical shaft and the parts carried by the latter respectively, is revolubly supported from said frame;

J" is a tubular partition around the shaft y and depended from the frame G above the spokes w,

3f) and inwardly defining the discharge passage Q thereabove;

y' is the upper outer wall of the housing I-I, shown in the form of a truncated cone spaced from and around the casing P;

55 h is an annular fanway or space between the casing P and the wall y and in which the b-lades I revolve; v

z" are the inner edges of the fan blades I, shown as upstood above the spokes w;

Il" are the horizontal lower inner edges of the fan blades I, shown as cutaway above and around the die A;

k is a conically recessed annular bottom flange on the frame G and around and receiving the upper end of the wall y;

Z' are bolts fastening the wall y in the flange 70';

m is the lower wall of the housing H, shown as an inverted conical member connected base to base on the conical member g'; 5 11 are bolts connecting the members y' and m';

o are support brackets within the wall m';

1J is the top wall for the filter K;

q are the inclined lower ends of the lter K; l0

s is an elevator for supplying material to be pulverized to the pulverizer;

t is a conveyor extended from said elevator to the hopper of the pulverizer;

w is a hopper carrying the supply pipe D from T5 the frame G;

V is a cover for the frame G;

y is a vertical conduit through the hopper w' above and coaxial with and in communication with the pipe D, for vertically precipitating 20 coarser material toward the latter;

z is a lateral conduit in the hopper w and in communication with one side of said vertical conduit, for laterally supplying inverted material thereto at said side thereof; 25

a2 is a cover for the hopper w';

b2 is a sustainer wall within the conduit y and opposite and spaced from the conduit a', adapted to laterally sustain opposite the latter coarser Z, material precipitated through the former; 30

yc2 is a belt drivenby the shaft for driving the conveyor t therefrom;

d2 is a conveyor pulley driven by the belt c2;

e2 is a conveyor shaft driven by the pulley d2; r

f2 are bevel gears driven by the shaft e2; 35

g2 is an elevator pulley driven by the bevel gears f2;

h2 is an elevator belt driven by the pulley g2;

i2 is an elevator pulley driven by the belt h2;

7'2 isa gas inlet to the hopper w; 40

k2 is a gas chamber within the hopper w and in communication with the inlet 7'2;

Z2 is a gas conduit within the hopper w and around the wall b2 and in communication from the chamber k2 to the vertical conduit D; '45

mi2 is an annular gas chamber between the distributor C' and the wall W, for collecting gas therebetween;

o2 are tubular gas conduits in communication from the gas chamber m2 up through and above 50 the distributor C, for up-passing gas past the latter;

p2 is a vertical annular gas conduit around the pipe D and within the shaft n, and in communication with the conduits o2, for up-passing gas 55 therefrom;

q2 is an annular gas chamber around the hopper w and in communication from the conduit p2 to the chamber k2 for conducting gas therebetween; 60

r2 is a gas pipe in communication from below the wall e' of the frame G to within the chamber k2 in the hopper w', for conducting gas therebetween;

s2 is an annular gas chamber in the frame G and in communication above and around the Wall y with the fanway h', for receiving gas above and from the latter and conducting it to the pipe r2; 70

t2 is a valved gas pipe in communication with the pipe 12, for controlling supply thereto of, or removing therefrom, gas;

u2 is a valve for the pipe r2 for controlling flow therethrough; 75

tra

from Vsuch coarser material, and a receptacle N is provided forlsuch screenings, in the form u2 is an annular gas 4trap around the outlet LZ, for collectinggastherearound;` l

m2 is a gas outlet fromand `in ,communication with the `trap v2, for removinggas therefrom;

:r2 is a gas pipe in'communicaton fromY the gas trap v2 to the gas chamber s2, for transferring gas therebetween;

y2 is a gas supply pipe in communication with' vand other parts of the device.

As shown the shaft n movab-ly suspends and rotates" the distributor C, r'olls B, land uptossers A', and the shaft e movably supports androtates the diev A and the casings P and R connected therewith, and the shaft y supports and rotates `the fan blade'sI, and each of these parts is revolubly suspended from Athe frame G and relative- `ly revoluble within and concentric of the housing H, whichhisshown as non-rotatively depended from the frame In such pulverizers the wall W has constituted a bottom wall for the return' current passage X and a retainer'` wall for retaining within the pulverizer coarser material, until allA of such material was returned to the crushing elements by the uptossersA and completely pulverized, a construction endangering clogging of the pulve'rizer in case'the rate of feed to it exceeded 'l f the rate at 'which it could finish pulverization `of the material; and the wall under the dropper outlet, for receiving coarse material dropped therefrom, has extended acrossvthey zone of precipitation from said outlet, and 'has supported `rater with a coarse material ydischarge means below said dropper outlet and below the zone of the returning current; for receiving coa-rser material vdropping through said outlet and discharging it from below said zone to externally o f the pulveri'zer, for Iaccomplishing which purpose,

Y is a coarsematerial discharge means 'below `the dropper outlet `n2 andthe wall W and the return current passage X, and extended there@ from' in the form of lan inverted truncated cone "having an upper end spaced `around the periphery of the wall W and vin communication around said periphery with the dropper outlet n2 and the nested. to the ,elevator s' for `returning..coarser v material to the hopper passage X, which lcone is disposed inwardly `of 'the dust chamber L and concentricallyfwithin the housing I-I, .and fisgin communication from within to without the latter, and receives coarse :material from and around `the wall W and con veys` and discharges it Vbelow the latter, and inwardly of the dust chamber, through a dis.-

-charge outlet Zy extended from said cone to .ex-

ternally ofthe housing and shown as con- ,As' shown `.the cone Yis a foraminous screen, for screening material of intermediate lineness of an inverted cone, having an imperforate wall u' runder and around thecone .Y and spaced inwardly of l and concentrically of the wall m', for vreceiving such intermediate material and downwardly conveying it inwardly of the dust chamber and across the latter to externally thereof, through an outlet O in communication from the chamber N to externally of the housing H, and i the cone u is shown as carried from the cone m by Athe brackets ol', and the cone Y is shown as yieldably carried fromthe cone u' by springs.

'11', andthe .upper ends of the cones u and Y are shown as spaced inwardly of and surrounded by the lter K. In this construction the cones Y and u'lconstitute complementary parts of exlternally'extended discharge means adapted t0 classify said dropped material into coarser and intermediate-grades, and to freely separately discharge these grades to externally ofA the housing; i

Another feature of my invention avoids molestation of the connectionbetween the die A and the casings P and R and the overhead support` 'and rotation-means therefor by disposing said connection' entirely above the zone of distribution of said material, connecting it to said parts above said zone, and constructing it to support h.

and rotate said parts from said overhead support and rotation means from without and above the space below said dropper outlet and the zone Vof precipitation of `coarse material from the latter, t accomplish which I make the spoke means c circumferentially. spaced and extend them across thev upper current outlet Q in such manner that the separa-ting current may discharge through the spaces between them, and dispose them above the die A and rolls B and distributor C and abovethe zone of distribution and entirely without the space below the dropper outlet n2', and connect them to the die above the latter, preferably by upwardly inclining the spoke means from the-hub d toward and connecting them `to thel upper part o-f the casing P, and

connecting the latter tothe die A and the casing R bybolts b therebetween, in such manner that molestation' by such connection of the crushing. chamber and dropper outlet therebelow avoided. l

Another feature vof my invention aims to facilitate discharge of coarse material below the dropper outlet n2 `and below the current passage X, and to-'this end Ipreferably lmake the bottom wall Wj of the latter as a rotatable disc oppcsite and spaced below said dropper outlet a distance equal to the height of said passage, in communication from the latter to externally thereof and constructed to receive dropped material. below said passage and to rotatably discharge it from thereunder to externally thereof, preferably as shown bysuspending and rotating it from the distributor C, and constructing it as la disc the outer periphery of which is inwardly of and spaced from and in communication with the external discharge means` Y, in

such manner that rotation of the bottom wall W centrifugally -ischarges material thereon into the cone Y,. forv scraping which the wall W is Preferably provided with and rotates a scraper r inwardly of and adjacent the cone Y and extended above the latter within and adjacent inclined annular latter and the open upper ends ofthe cones Y Vand u', which valve is preferably carried and rotated from 'the wall W by the Scrapers 1, and

'resists upflow of current from the dust chamb'er L therearound.

Another feature of my invention provides for limiting the rate of external discharge of uncrushed material to a predetermined depth of such material sustained by the wall W, and this kis preferably accomplished by spacing the uptosser meansA a distance above said wall equal to said depth, to the end that they may uptoss or return to the pulverizing elements only such material in excess of such depth as is sustained by said wall, so that centrifugal discharge of dropped material from the wall W may be limited to that `within the spaced distance between said wall and said uptossers. j

Another feature of my invention provides for yreturning vfrom the. wall W to the pulverizing elements larger material than it is` desired to centrifugally discharge from such wall, and this is preferably accomplished by spacing between the latter and the uptossers A' inward conveyor or inrpusher means B', shown as carried by and rotatable with the casing R and depended outwardly of and below the inlet S and inwardly across the dropper outlet n2 and the wall W to and in communication with a receptacle or grit pocket C centrally of and carried bythe wall W, in such manner that the inpushers B' will inwardly convey material from a spaced distance above the wall W into the pocket C', while permitting said wall to rotatablydischarge material thereon below said inpushers, and by providing a screw elevator means D' in communication from the pocket C"to a return passage F' below the distributor C and abovev an annular centrifugal means G rotatable therewith and around the casing I-I' rotatable with the distributor G' and in the form of an inverted truncated cone the smaller lower end of which is in communication with the pocket C `and the upper end of'which opens into the passage F', in such manner that vmaterial kin the pocket C' will be elevated therefrom bythe screw D' and casing I-Iy to the passage through which it will be outwardly projected by the annular distributor G' toward the inner .fe-ce of the die A' against which it may be further pulvcrized by the rolls B.

otherfeature of my invention provides for istably controlling infeed of uncrushed material through the lateral leg a' of the hopper w" by the vertical descent of material through the vertical leg y of the latter, and thisis preferably `movable to adjust the width of the baffle which tbe partition b2 affords opposite the fresh feed inlet a'.

lIn the construction shown the lower ends I of 'the fan blades I are inclined for downwardly impelling the current discharged by them, and a ring of filter troughs J is mounted around the die A and filter K and inwardly of the ends I' of the ian blades, and is covered by a ange K carriedl by the die for resisting leakage between it and said troughs. As shown the outlets M and O yare closed by gravity valves L.

In operation with the construction shown uncrushed material dropping from the crushing elements will fall through the returning current to and be sustained on the wall W, by which itwill be rotatablyoutwardly moved under the return current passage X yand pass below the latter and Y, by which it will be downwardly and outwardly discharged'from below the returning current to externally of the latter and the housing H.

The uptossers A' will limit the rate of discharge from the vwall W to-such material sustained by :als

the latter as is below the spaced distance between 4the uptossers and said wall', and will return to the crushing elements material above said distance. The inpushers B spaced between the uptossers A' and the wall W, will inwardly convey part of the material sustained on-vsaid wall therebetween, and the receptacle C' willcollect such part of said around the periphery of the wall W into the cone "-"10 material, which will be elevated by the screw D' through the hopper-,Hvtc the annular distributor G', by which it will be redistributed to the crushing elements. Support and rotationof the pulverizing elements will be eected without molestation of the' zone of precipitation of uncrushed material from the vdropper outlet.

It will-be understood that my invention is not limited to the particular details of construction, use, arrangement, or combination of parts, set forth as constituting its preferred form, since it may be availed of, in whole or in part, according to' such modifications of these as circumstances, or the judgment of'those skilled in the art, may dictate, without departing from the spirit ofthe invention.

What I claim is:

1. In a pulverizer, a main frame or casing, an'

annular horizontal die therein for discharging ne material, and dropping uncrushed'material as tailings, carried bysaid frame-and having an internal `annular crushing face,a-rotatable crushing roll within and eccentric vof said die and having a peripheral crushing face toward said face for crushing material between said faces, supply means for supplying material to be crushed by said faces, drive means for rotating said roll, a material sustainerl wall belowsaid die, for receiving and sustaining such uncrushed material .dropped from said die, rotary material uplifters inwardly of said die and above said wall, for up- '.tossinguncrushed material from said wall toannularhorizontal ldie therein for dischargingv nematerial; and dropping uncrushed material as. tailings, carried by said frame and having an internal annular crushing face, a rotatable crushying roll withinand eccentric of said die and having a peripheral crushing face vtoward'said 'face' for crushing material between said faces,

supply means for supplying ymaterial to be crushed by said faces, drive means for rotating said roll, a material sustainer wall below said die, for receiving and sustaining'such uncrushed material dropped from said die, rotary inpushers above and adjacent said wall, vfor inwardly pushing such uncrushed material over said wall, and a rotary refeeder above said inpushers, for receiving and refeeding such inpushed material to said die.

V3.7In`apulverizer, a main frame or casing, an annular horizontal die therein for discharging ne material, anddropping uncrushed material as tailings, carried by said frame and having an internal annular crushing face, a rotatable crushing roll within `andeccentric of said die and having a peripheral crushing face toward said face for crushing material `between said faces, supply means for supplying material toy be crushed by said faces, drive means for rotating said roll, a material sustainer wall below said die, for receiving and sustaining such uncrushed material dropped from said die, inward conveyor means below said die and above said wall for inwardly conveying such uncrushed material falling from said die, and `rotary refeeder means inwardly of said conveyor means for receiving and refeeding such inwardly conveyed material to said die.

4. In a'pulverizer, a main frame or casing, an annular horizontal die therein for discharging fine material, and dropping uncrushed material as tailings, carried by said frame and having an internal annular crushing face, a rotatable crushing roll withinand eccentric of said die and having a peripheral crushing face toward said face for crushing material between said faces, supply means for supplying material to be crushed by said faces, drive means for rotating said roll, a material sustainer wall below said die, for receiving and sustaining such uncrushed material dropped from said die, inward conveyor means below said diev and above said wall for inwardly conveying such uncrushed material falling from said die, and uplifter means inwardly of said inward conveyor means for receiving and uplifting said inwardly conveyed material into said die.

5. In a pulverizer, a `main frame or casing, an annular horizontal die therein for discharging fine material, and dropping uncrushed material as tailings, carried by said frame and having an internal annular crushing face, a rotatable crushing roll within and eccentric of said die and having a peripheral crushing face toward said face for crushing material between said faces, supply means for supplying material to be crushed by said faces, drive means for rotating said roll,

a material sustainer wall below said die, for receiving and sustaining such uncrushed material dropped from said die, and classier means intermediate said wall and said die for classifying such dropped material, comprising an. upper inpusher for refeeding coarser dropped material fand a lower discharger for discharging fine dropped material as tailings, and atailings receiver conveyor for receiving and conveying such tailings.

6. In a pulverizer, a main frame or casing, an` annular horizontal die therein for discharging ne material, and dropping uncrushed material as tailings, carried by said frame and having an internal annular crushing face, a rotatable crushing roll within and eccentric of said die and having a peripheral crushing face toward said face for crushing material between said faces, supply means for supplying material toy be crushed by said faces, drive means for rotating said roll, a material sustainer wall below said die, for receiving and sustaining such uncrushed material dropped from said die, inward conveyor means below said die and above said wall for inwardly conveying saiduncrushed material falling from said die, and a rotary upwardly and outwardly flared refeeder inwardlyV of and spaced from said die, in communication with said conveyor means and in communication therefrom to inwardly of said die, for refeeding such uncrushed material from said wall to said die.

` '7. In a pulverizer, a main frame or casingv an annular horizontal die therein for discharging fine material, and dropping uncrushed material as tailings, carried by said frame and having an internal annular crushing face, a rotatable crushing roll within and eccentric of said die and having a peripheral crushing face toward said face for crushing material between said faces, supply means for supplying material to be crushed by said faces, drive means for rotating said roll, a material sustainer wall below said die, for

receiving and sustaining such uncrushed material dropped from said die, inward conveyor means below said die and above said wall, for inwardly conveying uncrushed material falling from said die, and a spiral uplifter above said wall and spaced inwardly of said die, in communication with said conveyor'means and in communication Atherefrom to` inwardly of said die, for refeeding a material sustainer wall below said die, for

receiving and sustaining such uncrushed material dropped from said die, inward conveyor means below said die and above said wall, for inwardly conveying said uncrushed material falling from said die, an uncrushed material receptacle inwardly of and encircled by said wall,

in communication with said conveyor means andy adapted to receive therefrom such uncrushed material, and a refeeder above and in juxtaposition to said receptacle, in communication therewith and in communication therefrom to inwardly of said die, and adapted to receive said uncrushed material from said receptacle, and to refeed said uncrushed material into said die.

9. In a current recirculation pulverizer, a casingenclosing a settling chamber, means mounted within and in spaced relation to said casing enclosing a crushing chamber, having an upper current outlet and a lower current inlet in communication with said settling chamber, and affording an endless current passage up through, out over, and down around, said crushing chamber, and a return current passage under the latter, support means for said casing, supply means in communication with said crushing chamber, for supplying Vmaterial therein, crushing elements within said crushing chamber, for crushing said material, operator means for operating said elements, blower means in communication with said passage and adapted to kcirculate a separating fluid current up through, out over, and down around, said crushing chamber and in through said return current passage, for oating fine material into .saidsettling chamber, bottom wall means for said return current passage, below the, latter and within and spaced from said casing', particle interceptor means around said bottom wall and extended vertically across said return current passage, for intercepting particles floating in said current toward said return current passage and dropping saidv particles into said settling chamber, and rotatable shelf means around said wall means and extended therefrom below and adjacent and across said interceptor means, adapted to receive and to rotatably discharge said particles precipitated therefrom toward said settling chamber, and to resist current leakage between said wall means and said interceptor means.

l0. In a pulverizer, a casing enclosing a crushing chamber having an outlet for ne material and `a dropper outlet for` coarser material, support means for supporting said casing, supply means for supplying material to be crushed in said chamber, comprising a vertical conduit in communication with said chamber, for vertically precipitating coarser material there toward, and a lateral conduit in communication with one side of vsaid vertical conduit, for laterally supplying uncrushed material thereto at said side thereof,

crushing elements within said chamber fork crushing. said material, and operator means for operating said elements; the combination therewith of an adjustable inner wall for said vertical conduit within and at the other side thereof,

opposite and spaced from said lateral conduit, adapted to laterally sustain opposite the latter said coarser material precipitatedthrough said vertical conduit, and adjustable relatively to said lateral conduit for varying said sustenance.

ments an open dropper outlet for dropping coarser material'through said current to below the zone thereof and externally of said chamber, and coarser material discharge means below said dropper outlet, in communication therefrom below the zone of said current to and extended externally of said casing.

12. In a pulverizer comprising, an annular casing rotatable around a substantially vertical axis and enclosing a crushing chamber having an upper current outlet and a lower current inlet, supply means distributing material to be crushed in said chamber, crushing elements within said chamber, operator means for said elements, blower means upfloating i'lne material from said elements and permitting coarser material to drop therefrom, said chamber having below said elements an open dropper outlet dropping coarser material through said current to below the zone thereof and to externally of said chamber, coarser `material discharge means below said dropper outlet, in communication therefrom below the zone of said current to and extended externally of said casing, rotary means rotatingsaid casing, and support means for said parts; the combination therewith of a rotation connection between and rotatable with said rotary means and said casing, disposed entirely above the zone of said distribution, connected to said casing above said zone, and constructed and arranged to rotate said casing from ,said rotary means from above said zone', and from without andabove the space below said dropper outlet.

' 13. In a current recirculation pulverizer comprising, aicasing enclosing a return current passage, means'spaced within said casing enclosing a crushing chamber having an upper current outlet and a lower current inlet in communication with said passage and 1affording therewith an endless current `passage up through and down around said crushing chamber, supply means dis-v tributing material to be crushed in said crushing chamber, crushing elements within said crushing chamber, operator means for said elements, blower means upfloating fine material from said elements and permitting coarser material to drop therefrom, said chamber having below said ele-A ments an open dropper outlet above said return current passage, for dropping coarser materialv through said current to belowthe zone thereof and externally of said chamber, and support means for said parts; the combination therewith of coarser material discharge means below said dropper outlet and below said return current passage, in communication therefrom below the zone of said current to and extended externally of said casing, comprising a rotatable bottom wall below and for said return current passage, opposite and spaced below said dropper outlet `a distance equal to the height of said return current passage,` in communication from the latter to externally thereof, and constructed and arranged to receive said dropped material below said return current passage and to rotatably discharge it from thereunder to externally thereof.

14. In a current recirculation pulverizer comprising, a casing enclosing a return current passage, means spaced within said casing enclosing a crushing chamber having an upper crushed material outlet and a lowerA uncrushed material dropper outlet in communication ywith said passage and affording therewith an endless current passage up through and down around said crushing chamber, supply means for material to be crushed in said crushing chamber, crushing elements within said crushing chamber, blower means forl upfloating crushed material from said elements, discharge means opposite and below said dropper outlet, and below said return current passage, in communication Afrom below the latter to externally of said casing, operator means for said elements, and support means for said parts; the combination therewith of uptosser means inwardly of andibelow said dropper outlet, spaced a distance above said discharge means, in communication from said spaced vdistance above the latter up through said dropper outlet and with said elements, and constructed and arranged to return to the latter from said distance above said discharge means material on the latter above said distance, and to limit the discharge by said discharge means' to material on the latter below said distance.

15. In a current recirculation pulverizer comprising, a casing enclosing a return current passage,an annular Acrushingv die rotatable around a substantially vertical axis, lspaced within said casing and having an inner annular crushing face enclosing a crushing chamber having an upper crushed material discharge outlet and a lower uncrushed material dropper outlet in communication with said passage and affording therewith an endless current passage up through and down varound said chamber, supply'means for thedistributionaof material to be crushed in said chamber, a rotatable crushing roll within and eccentric of said die and having a peripheral crushing face reciprocal to said face for crushing said material between said faces, rotatable blower means for upfloating fine material from said faces and permitting coarser material to drop therefrom, and externally extended discharge means for said uncrushed material below said return current passage and opposite and spaced below said dropper outlet a distance equal to the height of said return current passage, and in communication from below the latter to externally of said casing, and support means forsaid parts; the combination therewith of rotary means above and for rotating said die, disposed above the zone of said distribution, and entirely without the space between said dropper outlet and said discharge means, connected to said die above said zone, and constructed and arranged to rotate said die from above and entirely without said space.

16. In a pulverizer comprising, a horizontal die rotatable about a substantially vertical axis and having an inner annular crushing face enclosing a crushing chamber having an upper ne material discharge outlet and a lower uncrushed material dropper outlet, a rotatable crushing roll within and eccentric of said die, having a peripheral crushing face cooperable with said face, for crushing material between said faces, supply means for distributing material to be crushed to said faces, and support means for said parts; the combination therewith of means for rotating said die having circumferentially spaced discharge passages above the zone of said distribution, above said annular face and extended across said upper outlet, connected to said die above said zone, entirely above said dropper outlet, and constructed and arranged to pass said discharge from above said zone, and to rotate said die from above the latter and from above and entirely without the space below said dropper outlet.

GEORGE HOLT FRASER. 

